What type of code do I need to sell a book?

Books often require an ISBN (International Standard Book Number). An ISBN number and a scannable bar code are separate items. Bookstores always require ISBN's, but if you’re planning on selling your book elsewhere it’s worth your while to determine whether the retailer will accept a UPC or EAN bar code instead. If you purchase an ISBN number and need it converted into a scannable bar code, Bar Codes Talk can do that for you. Contact Us! If your retailer will accept a UPC or EAN bar code, we can supply you with everything you need. 

ISBN's must be purchased in your country of residence. If you live in the United States, you can buy them here: http://isbn.org/standards/home/index.asp